Electric switch



Aug. 25, 1925.

S. DWORKIN ELECTRIC SWITCH Filed April 18, 1923 W Z mm m 4 m I Z, a Mr HJ E m 6 a m G W m H F a H Patented Aug. 25, 1925.

UNITED STATES SAMUEL DWORKIN, OF PHILADELPHIA, PENNSYLVANIA.

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Application filed April 18, 1923. Serial No. 632,821.

7 '0 all whom it may concern:

Be it known that I, SAMUEL DwoRKIN, a citizen of the United States,residing at Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented a certain new and useful Improvement inElectric Switches, whereof the following is a specification, referencebeing had to the accompanying drawing.

My invention is particularly applicable to switches of the portableautomatic cutout type, adapted for use in connection with electricstoves, sad irons, fans, etc., to detachably connect such devices with asource of energy and to automatically break the circuit if and when anysuch connected device is upset from its normal position.

As hereinafter described; my invention includes a switch of the portableplug type having recesses and contacts for electrical connection withtwo parallel pin terminals upon the device which is to be supplied withenergy and having a movable switch element which is a ball adapted togravitate to make and break connection between two terminals in theswitch; one of said switch terminals being a tube in which the ball ismounted to roll in continuous contact therewith, and the other terminalbeing an abutment opposed to the end of said tube in such relation thatsaid ball contacts therewith when the device is in normal position, butrolls away when upset.

My invention includes the various novel features of construction andarrangement hereinafter more definitely specified.

In said drawings; Fig. I is a front elevation of a switch convenientlyembodying my improvement.

Fig. II is a side elevation of said switch.

Fig. III is an elevation of said switch, similar to Fig. I, but with thefront section of the switch casing removed to show the interiorconstruction and arrangement.

Fig. IV is an elevation of the lower end of said switch as shown in Fig.I.

In said figures; the switch casing is conveniently formed of twocomplementary sections 1 and 2 of insulating material. Said sectionshave recesses arranged to hold two pairs of spring contacts 3 and 4adapted to resiliently engage the two parallel pin terminals 5 and 6 ofthe device 7 which is to be supplied with electrical energy.

Said casing is also recessed to hold the movable switch element which isthe ball 9 which is adapted to gravitate to make and break connectionbetween the terminals 10 and 11; the latter being a metal tube and theformer a metal abutment. Said terminals l0 and 11 are convenientlyinsulated from each other by cementing them in the cylindrical glasstube 12. Said tube 12 has metallic end closures 14 and 15 respectivelyin electrical connection with said terminals 10 and 11 and provided withrespective binding posts 16 and 17 The contact 11 is convex and opposedto the ball 9 and when the parts are in their normal position, as shownin Fig. III, the convex portion 11 will cause the ball 9 to slightlyshift or move laterally to insure a good electrical contact with theinner wall of the tube 10. Thus the ball 9 can move lengthwise or in thedirection of the axis of the tube 10 and upon gravitating in contactwith the convex terminal 11, the latter, due to its curvature, willca'use a slight rolling or shifting movement of the ball laterally toeffect said contact of the ball with the inner surface or wall of thetube 10.

Said binding post 16 is electrically connected with the conductor 19extending into the cable 20 leading to the source of electrical energy.Said binding post, 17 is electrically connected with the contacts 4 bythe conductor 22. Said contacts 8 are electrically connected with theconductor 24 which also extends in said cable 20.

Said cable 20 is flexible and is provided with the spring guard 25formed of helically coiled wire, the terminal convolutions 27 of whichare of larger diameter than the others and adapted to engage the recess28 in said casing and prevent accidental removal of said guard. Saidcable 20 may be provided at its other end with any suitable electricalconnecting means such as an ordinary screw plug adapted for connectionwith a municipal supply circuit including a source of electrical energy.The bolts 29 and nuts 30 detachably connect. said sections 1 and 2.

It is to be understood that when said switch is in the upright positionshown in Figs. I to III inclusive; said ball 9 rests upon said abutmentterminal 11 which is convex so that said ball tends to gravitatesidewise and maintain its contact with the tubular terminal 10 unlessand until said switch is upset to the position indicated in Fig. IV.whereupon, said ball 9 rolls away from said abutment. terminal 11 andthus breaks the electrical supply circuit which it otherwisecontinuously maintains.

Of course, the contacts in said switch casing may be arranged andadapted for detachable electrical connection with forms of terminalsother than the parallel cylindrical pins above described and, although Ihave found it convenient to use a piece of cylindrical glass tubing asthe insulating medium between the terminals to be connected by themovable ball; other insulating means may be employed. Therefore, I donot desire to limit. myself to the precise details of construction andarrangement herein set forth, as it is obvious that variousmodifications may be made therein, without departing from the essentialfeatures of my invention, as defined in the appended claims.

I claim:

1. In an electric switch, the combination with a portable casing of twocontacts seated in said casing and adapted for detachable connectionwith a pair of terminals of a device to be supplied with electricalenergy; an electric conductor extending from one of said spring contactsinto a flexible cable extending exterior to said casing; a movableswitch element in said casing, consisting of a metal ball; an insulatingtube surroundinn; said ball; a convex abutment extending into the lowerend of said tube; a closure cemented to the lower end of said tube, inelectrical connection with said abutment and having a binding post; anelectric conductor detachably connecting the other of spring: contactswith said binding post; a tubular metallic terminal extending in theupper end of said tube in opposition to said abutment and between saidtube and said ball; a closure for the upper end of said tube, inelectrical connection with said tubular terminal; a binding post uponsaid closure in .electrical connection with said tubular terminal; aconductor detachably connected with the last named binding post andextending into said cable; whereby said ball is continuously maintainedin electrical connection with said tubular terminal, and is normallymaintained in electrical connection with said abutment terminal, bygravitation of said ball, but said ball is automatically separated fromsaid abutment to break the circuit by gravitation of said ball, whensaid switch is upset to abnormal position.

2. In an electric switch, the combination with a portable casing; springcontacts seated in said casing, adapted for detachable connection with apair of terminals of a device to be supplied with electrical energy; anelectric conductor extending from one of said spring contacts, into aflexible cable extending exterior to said casing; a movable switchelement in said casing, consisting of a metal ball; an insulating tubeencircling said ball; a convex abutment extending into the lower end ofsaid tube; a closure for the lower end of said tube, in electricalconnection with said abutment; an electric conductor detachablyconnecting the other of said spring contacts with said abutment; atubular metallic terminal extending in the upper end of said tube inopposition to said abutment and between said tube and said ball; aclosure for the upper end of said tube, in electrical connection withsaid tubular terminal; and a conductor electrically connected with saidtubular terminal and extending into said cable; whe l ball is continuously maintained in electrical connection with said tubularterminal, and is normally maintained in electrical connection with saidabutment terminal by gravitation of said ball, but said ball isautomatically separated from said abutment to break the circuit bygravitation of said ball, when said switch is upset to abnormalposition.

3. In an electric switch. the combination with a portable casingformedof insulatin" material; of spring contacts seated in said casing. andadapted for detachable connection with terminals of a device to besupplied with electrical energy; an electric conductor extending fromone of said spring contacts, into a flexible cable extending exterior tosaid casing; a movable switch element in said casing, consisting; of ametal ball; an insulating; tube encircling said ball; a convex abutmentextending into the lower end of said tube; a closure for the lower .endof said tube, in electrical connection with said abutment: an electricconductor detachably connecting; the other spring contact with saidabutment; a tubular metallic terminal extending); in the upper end ofsaid tube in opposition to said abutment and between said tube and saidball: a closure for the upper end of said tube, in electrical connectionwith said tubular terminal; and a conductor detachably connected withsaid tubular terminal and extending into said cable; whereby said ballis continuously maintained in electrical connection with said tubularterminal, and is normally maintained in electrical connection with saidabutment terminal, by gravitation of said ball, but said ball isautomatically separated from said abutment to break the circuit by"ravitation of said ball, when said switch 1s upset to abnormalposition.

4;. In an electric switch, the combination with a casing having abranched recess, of two contacts respectively mounted in the branches ofsaid recess; a cable leading into said recess and having" twoconductors, one conductor leading directly through one of the branchesto the contact therein; a metallic tubular terminal for the otherconductor in said other branch of the recess; an abutment in electricalconnection with the other of said contacts and held in spaced relationfrom the lower part of said tubular terminal; and a metallic gravitatingmember movably engaging within said tubular terminal and adapted, whenthe casing is in an upright position, to move into engagement with saidterminal abutment to electrically bridge the space between the tubularterminal and said abutment- 5. In an electric switch, the combinationwith a casing; of two contacts carried by said casing, adapted fordetachable connection with a device to be supplied with electricalenergy; a movable switch element in said casing, consisting of aspherical metal ball; a glass tube encircling said ball; a convexabutment extending into one end of said tube; a closure secured to thatend of said tube, in electrical connection with said abutment; a tubularmetallic terminal extending in the other end of said tube in oppositionto said abutment and between said tube and said ball; a closure for thatend of said glass tube, in electrical connection with said tubularterminal; a flexible cable extending from said casing, including twoconductors, one leading directly to one of said contacts, and the otherconductor connected to said other contact through said switch terminalsand ball; whereby said ball is continuously maintained in electricalconnection with said tubular terminal, and is normally maintained inelectrical connection with said abutment terminal, by gravitation ofsaid ball, but said ball is automatically separated from said abutmentto break the circuit by gravitation of said ball, when said switch isupset to abnormal position.

6. In an electric switch, the combination with a casing; of two contactscarried by said casing, adapted for detachable connection with a deviceto be supplied with electrical energy; a movable switch element in saidcasing, consisting of a metal ball; an insulating tube encircling saidball; a metallic abutment terminal extending into one end of said tube;a closure secured to that end of said tube, in electrical connectionwith said abutment; a tubular metallic terminal extending in the otherend of said tube in opposition to said abutment and between said tubeand said ball; a closure for that end of said glass tube, in electricalconnection with said tubular terminal; and two conductors, one leadingdirectly to one of said contacts, and the other conductor connected tosaid other contact through said switch terminals and ball; whereby saidball is continuously maintained in electrical connection with saidtubular terminal, and is normally maintained in electrical connectionwith said abutment terminal, by gravitation of said ball, but said ballis automatically separated from said abutment to break the circuit bygravitation of said ball, when said switch is upset to abnormalposition.

7. In an electric switch, the combination with a casing; of two contactscarried by said casing, adapted for detachable connection with a deviceto be supplied with electrical energy; a tubular metal terminal in saidcasing; a metal ball mounted to roll in said tubular terminal; a convexabutment terminal opposed to said tubular terminal for deflecting theball laterally into contact with the side wall of said tubular terminal;and two conductors, one leading directly to one of said contacts, andthe other conductor connected to said other contact through saidterminals and ball; whereby said ball is continuously maintained inelectrical connection with said tubular terminal, and is normallymaintained in electrical connection with said abutment terminal, bygravitation of said ball, but said ball is automatically separated fromsaid abutment to break the circuit by gravitation of said ball, whensaid switch is upset to abnormal position.

In testimony whereof, I have hereunto signed my name at Philadelphia,Pennsylvania, this 12th day of February, 1923.

SAMUEL DWORKIN.

